Emission legislation that is steadily becoming more stringent both for on-highway as well as for off-highway applications is characterized by a clear reduction of the particle emissions. The particle emissions of the internal combustion engines also include the oil that is combusted in the internal combustion engine, which in addition to the blowby from the crankcase is also created through the design-related oil leakage of the exhaust gas turbocharger. Reliable oil sealing thus becomes ever more important. Popular oil seals in this case usually have the following features: use of at least one, maximally two shaft sealing rings between sealing bush and bearing housing cover, minimisation of the axial gaps between bearing housing cover, sealing bush, axial bearing and thrust washer, provision of oil baffle plates, which prevent oil entering a region between sealing bush and bearing housing cover and provision of an undercut in the bearing housing cover, which collects the spun-off oil, returning it into an oil reservoir of the bearing housing through a circumferential groove.
From US 2007/0092387 A1 a generic internal combustion engine with a shaft that is mounted in a bearing housing and carries a compressor wheel as well as a turbine wheel is known, wherein for sealing the bearing housing with respect to the compressor side, a sealing bush that is arranged on the shaft in a rotationally fixed manner is provided, which together with the bearing housing cover at least partially delimits an annular oil centrifuging space that is arranged coaxially to the sealing bush. The bearing housing cover in this case has an outer wall and an inner wall that is formed collar-like, which serves for collecting the separated oil and serves for passing on said oil as far as to an outlet opening on the bottom side. By way of this outlet opening or outflow opening, the oil that is separated in the oil centrifuging space and collected is returned to an oil reservoir.
From WO 2008/042698 A1 a further generic exhaust gas turbocharger with a shaft mounted in a bearing housing is known, wherein for sealing the shaft with respect to the compressor side, a sealing bush that is connected to the shaft in a rotationally fixed manner is provided, which interacts with a bearing housing cover. Here, the bearing housing cover in turn is designed in such a manner that it passes the oil that is separated in the oil centrifuging space to an oil drain on the bottom side.